Hi everyone,
I'm trying to build an h-bridge for an inverted pendulum type project (a segway, basically). I've been researching on how to build them (online and bought a book), and I think I'm kind of close to getting it, but I really don't know for sure. Any help would be greatly appreciated!
The project will use two identical 250W 24v / 13.7amp (Unsure of stall current, it's not documented as far as I can tell.) dc motors; Model: MY1016. Total load will be in the vicinity of 200lbs, shared amongst the two motors. The battery is a NiMH 24v / 40amps continuous output at a rating of 4200mAh, so I assume I am within an acceptable range to have both motors run off it exclusively.
The parts I have chosen are listed here: (I believe they all have a much higher rating than needed but I could be wrong, I'm a real newbie here.)
High side (p-channel) MOSFETs: http://www.st.com/stonline/products/literature/ds/8177/stp80pf55.pdf
Low side (n-channel) MOSFETS: http://www.vishay.com/docs/91328/91328irl.pdf
Half-bridge driver ICs (synchronous, with dead-time built in): http://www.irf.com/product-info/datasheets/data/ir2104.pdf
Diodes (really unsure if these will work correctly): http://www.diodes.com/datasheets/ds23001.pdf
I didn't label the capacitors in my schematic because I have no idea what ratings to use. I have read about the back-emf and electrical noise. I've seen a few h-bridges use 1uF capacitors for C1 through C4 (referring to my attached schematic) to eliminate most of the noise, but they were for smaller h-bridges so I don't know whether or not I should use them. C5 is supposed to absorb voltage spikes when the motor switches directions (the magnetic field collapses, sending power back into the circuit, right? or is this the job of the diodes, or both ), and give the circuit lots of power when it starts up again (also unsure on a good rating to use here, I just know it needs to be big), from what I understand.
The circuit design program I used (Pulsonix) left out some pins on the driver ICs, but I don't think they are really needed to address this problem (they are in the datasheet if needed though). I'd also like some feedback on if those are good drivers to be using, if possible.
If you need more information I'd be more than happy to get it for you. I tried not to leave anything out.
Again, any help is much appreciated, the tutorials I have read can't seem to answer this for me.
Thanks,
-Keith
I'm trying to build an h-bridge for an inverted pendulum type project (a segway, basically). I've been researching on how to build them (online and bought a book), and I think I'm kind of close to getting it, but I really don't know for sure. Any help would be greatly appreciated!
The project will use two identical 250W 24v / 13.7amp (Unsure of stall current, it's not documented as far as I can tell.) dc motors; Model: MY1016. Total load will be in the vicinity of 200lbs, shared amongst the two motors. The battery is a NiMH 24v / 40amps continuous output at a rating of 4200mAh, so I assume I am within an acceptable range to have both motors run off it exclusively.
The parts I have chosen are listed here: (I believe they all have a much higher rating than needed but I could be wrong, I'm a real newbie here.)
High side (p-channel) MOSFETs: http://www.st.com/stonline/products/literature/ds/8177/stp80pf55.pdf
Low side (n-channel) MOSFETS: http://www.vishay.com/docs/91328/91328irl.pdf
Half-bridge driver ICs (synchronous, with dead-time built in): http://www.irf.com/product-info/datasheets/data/ir2104.pdf
Diodes (really unsure if these will work correctly): http://www.diodes.com/datasheets/ds23001.pdf
I didn't label the capacitors in my schematic because I have no idea what ratings to use. I have read about the back-emf and electrical noise. I've seen a few h-bridges use 1uF capacitors for C1 through C4 (referring to my attached schematic) to eliminate most of the noise, but they were for smaller h-bridges so I don't know whether or not I should use them. C5 is supposed to absorb voltage spikes when the motor switches directions (the magnetic field collapses, sending power back into the circuit, right? or is this the job of the diodes, or both ), and give the circuit lots of power when it starts up again (also unsure on a good rating to use here, I just know it needs to be big), from what I understand.
The circuit design program I used (Pulsonix) left out some pins on the driver ICs, but I don't think they are really needed to address this problem (they are in the datasheet if needed though). I'd also like some feedback on if those are good drivers to be using, if possible.
If you need more information I'd be more than happy to get it for you. I tried not to leave anything out.
Again, any help is much appreciated, the tutorials I have read can't seem to answer this for me.
Thanks,
-Keith
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